Cant believe I found this goldmine of a channel… Excellent work!

Fantastic tutorial! I learned so much. I especially liked the explanation of the circles that turn into ellipses on the plane, but remain circles to the viewer. Bonus points for the low-tech and brilliant "moving the paper" to illustrate this. Also, showing how the cone of vision changes in area depending on how close or far away you are was incredibly helpful. I really like that you are hand-drawing these concepts because I can then recreate them by hand-drawing them. Thank you!

@trustyourperspective

5 ай бұрын

Great! Glad they were helpful

Love your channel man, I just started a Construction Drawing class for my first year in college and your channel covers alot of of the topics that're in the syllabus so I'll definitely be coming back to the channel throughout the semester.

One thing which confused me in the beginning is the idea that the picture plane can be located anywhere in the world of our viewer, and can be any size. It represents, in camera terms, our amount of zoom, crop, focal or lens length. It also represents the sheet of paper we're going to draw on! So imagine the plane is a piece of glass which is only one meter square and is placed one hundred meters away from us. We're going to look through it and trace on it (with our hundred meter long arms and superman vision!) what we see behind it. If we have a city scape, all we're going to get is a small portion of one building, perhaps a few windows. Our field of view or cone of vision (as captured on the glass) will be very narrow, less than one degree. But we have two problems. First, we can't capture anything that's closer than 100m, and secondly, we need very long arms. So we start to bring the plane of glass closer. But of course, as we do so, we need to shrink the size of the glass down i order to keep the field of view (cone of vision) the same. Because the cone gets smaller, the closer it gets to our viewer (eye or camera lens). So as we get the glass within arms length, it will need to be only a few centimeters square. If we don't shrink the size of the glass as we bring it closer, than our field of view gets progessively wider until, when it's at arm's length, it's giving us a field of view of roughly 60 degress. So when we see these representions of this big piece of glass (picture plane) in videos about perspective, we need to realize that its size and placement physically represent the image that will be captured, and its size needs to change, depending on what image we want to capture and where we place the glass. And for any given view, there are an infinite number of places we can place the glass along the cone, with the only limitation being that if it's too far or two close, we will not capture things in front of the glass, or things that are close will obscure what's behind. So in a sense, it doen't matter where we place the glass along that cone, but it's still useful to intuitively understand the concept that it can be moved back & forward, if we're willing to also change its size. Additionally, we need to realize that we need to make an extra conversion in size. Because although in our viewer's world, the sheet of glass is only a few centermeters square (in the above cityscape, zoomed in example), the piece of paper in our REAL world that we're drawing on isn't so small, it might be A4 or even a lot bigger. So then we realize we have a "real" world plane of vision in our viewer's world, but this needs to be shrunk down or blown up to the REAL world piece of paper we're actually drawing on! so I'm basically making the point that we have two worlds we need to think about in a physical sense: the "real" world of our viewer (in order to capture perspective), and our REAL real world (in order to represent perspective on a 2D surface). It's also important to note that, although analogies to photography and cameras can be useful, the analogy breaks down in the sense that a camera lens generally has a fixed, or a least limited field of view, whereas with our piece of paper, we're totally free to choose any lens length we want, even impossible (practically speaking) ones like an orthographic view! But of course we need to bear in mind the issues of distortion covered in this video.

Great explanation! This helped me a lot. I find perspectives to be quite interesting. I really just want to draw landscapes and nature, but I keep coming back to drawing buildings. I actually love drawing, even though I am not great at it, but drawing old farm houses and old town stores and train stations is fun. I would love to learn to draw and design courtyards and gardens scapes. I really hope you keep up the great videos!

@trustyourperspective

Жыл бұрын

Thank you. I'm glad they are useful. I'll probably keep doing them until I run out of things to say.😊

best video ive seen yet

@trustyourperspective

Жыл бұрын

Thank you 🙏

Does the distance between the viewer’s eyes play a significant role? Like, if you did the projection onto the image plane for one eye, and for the other eye, I imagine that for many things, the difference would be something relatively negligible (though of course one wouldn’t have stereoscopic depth perception looking at objects in the scene), but, is there a point where the discrepancy gets large enough that it becomes particularly noticeable? Also, the increased distortion outside the ~60 degree cone, is this just about, “if the viewer’s eye is not precisely at the ideal viewing point, then things outside this cone will look off”, or is it about like, some approximations failing for objects outside this cone? I would imagine that if the viewer’s eye was precisely at the right location (and they had their other eye closed), and if the image was exactly matching the correct perspective, then, it would look the same (perspective-wise) as if the scene were really there rather than the image? Is the issue “we want the picture to look good from multiple viewing locations”, or “it is very inconvenient/time-consuming/whatever to make the image have the distortions just right so that it looks correct from the one specific viewing location”? Or, something else of course. I could quite easily be missing a possibility or five. I’m not an artist, and am mostly interested in perspective for math reasons.

@trustyourperspective

29 күн бұрын

The distance between the eyes does not play a role at all because we eliminate one of the eyes. If you place the two eyes into the equation you end up with two different drawings (stereoscopic depth). Then you need a device of some kind (such as a stereoscope) so the left and right eye does not see the wrong image. "I would imagine that if the viewer’s eye was precisely at the right location (and they had their other eye closed), and if the image was exactly matching the correct perspective, then, it would look the same (perspective-wise) as if the scene were really there rather than the image?" Yes! Is the issue “we want the picture to look good from multiple viewing locations” Yes, this is why we keep it inside the 60°. It will always look perfect if we can force the viewer look at the scene from where the station point was plotted. but this is unrealistic so we try to limit the distortion by keeping the drawing inside the 60° cone of vision.

@drdca8263

29 күн бұрын

@@trustyourperspective Thanks!

How do I change the scale ratio? This is the thing that makes my mind glitch back and forth. I have a 1x1m canvas which people will see from 10m distance. So the canvas is a square in the picture plane. I cannot draw a line that is 10m. I have perhaps only a space of 2,5mx4m on my wall. If I fit my canvas in there it would be like zooming the image, i.e. shifting the picture plane to the front. But all I want to do is project an object on the canvas taking up the full area of it. Idk, maybe I'm trying to have my cake and eat it too. Somehow I have to narrow the vanishing lines of the object to project without shrinking it.

@trustyourperspective

Жыл бұрын

I may not be understanding what you are asking. But, I think you are saying that you have an image that you want to plot from a point where the viewer will be 10m from the picture plane. You want the picture plane to be your 1x1m canvas, but you can't plot the image because the 10m distance is too far away to fit on your perspective layout. Is this the question? At 10m a 1x1m image area would easily fit into the cone of vision so that will be no problem. To plot the image on a paper you would only need to scale everything down proportionally (e.g., make the distance 5m and the image area 0.5x0.5) then, when the drawing is complete you can enlarge the image to 1x1m. Is this the question?

@Libellisth

Жыл бұрын

​@@trustyourperspective Errrrgh, I keep flip-flopping on the focal point in my mind, unable to form an acute picture of what it is that I am trying to achieve. Alas confusion. No worries. I'm sorry; this interaction will not be helpful to anyone. It may in some regards be beneficial, however, perhaps, mayhaps. At any rate I wish to impress upon you, my sincerest gratitude for your making of these videos and the sharing of your perspective on this subject matter, with our world.

If everything is in one point perspective, then does the station point and cone of vision even matter?

@trustyourperspective

7 ай бұрын

Yes, depth will be distorted.